Saved Gantt Project file won't reopen

Hi, I created a project file, saved it and then it won’t reopen.
Error message says: [2023-11-23 01:06:32] [INFO][net.sourceforge.ganttproject] Starting RSS check…
[Fatal Error] :333:10: Character reference “&#11” is an invalid XML character.
Any ideas how to salvage the file? Can I edit the XML?

Yes, you can edit XML in any text editor. I believe that it will be enough to remove &#11 from the text and save the file.